Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1987-5-4
pubmed:abstractText
The tetrameric lactate dehydrogenases (LDH) of vertebrates contain several different subunits that arose by gene duplication. While the A and B subunits occur in all classes of gnathostomes, the enzymes of agnathans appear to represent two stages in the evolution of vertebrate LDH. Lampreys of the family Petromyzontidae have a single enzyme classified as LDHA4, while hagfish possess both A and B subunits which form only the two homopolymers LDHA4 and LDHB4. It is generally assumed that the original vertebrate LDH was an A4 type, that duplication to give the B subunit occurred prior to the divergence of lampreys and hagfish, and that modern lampreys subsequently lost expression of the B gene. Lactate dehydrogenases were purified from representatives of all three lamprey families, and it was confirmed that members of the Mordaciidae and Geotriidae also possess single tetrameric LDH enzymes containing one subunit type. The kinetic properties of the lamprey LDH enzymes were compared with the LDH homopolymers of hagfish, skate, and sardine. These properties did not allow the lamprey enzymes to be unequivocally identified as either LDHA4 or LDHB4. Immunochemical titration using antisera against lamprey and hagfish LDH homopolymers demonstrated that the lamprey LDH enzymes showed greater immunochemical similarity to LDHB4 than to LDHA4 of hagfish. It is concluded that there is little evidence for the claim that the original vertebrate LDH was an A4 rather than B4 type.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0022-104X
pubmed:author
pubmed:issnType
Print
pubmed:volume
241
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1-8
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1987
pubmed:articleTitle
Immunochemical evidence that the single lactate dehydrogenase of lampreys is more similar to LDHB4 than to LDHA4 of hagfish.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't